• Journal of Biosystems Engineering
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• v.39 no.2
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• pp.69-75
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• 2014

Purpose: This paper is aimed at analyzing the heating performance of the vertical closed loop type Geothermal Heat Pump System (GHPS) distributing the farm site and providing basic data of the GHPS. Method: Seedling greenhouse heating was made from October 2012 to May 2013. The seedling greenhouse was divided into 4 sectors (A, B, C and D zone, total $3,300m^2$) with different temperatures. It was heated from 5PM to 8AM, and during the night the greenhouse was covered by non-woven fabric thermal curtains along the upper 2m of the greenhouse for temperature maintenance. In order to analyze the heating performance of the GHPS, power consumption and operating time of the GHPS, inlet and outlet water temperature of the condenser, temperatures of each zone of the greenhouse, and ambient temperature were measured. Results: When operating only one heat pump unit, heat generated in the condenser decreased as the experiment progressed and power consumption increased correspondingly. However, the heating coefficient of performance decreased from 3.3 to 2.0 rapidly. Also, when operating two heat pump units, heat generated in the condenser decreased and power consumption increased. Heating coefficient of performance decreased from 4.5 to 3.7 rapidly. When the set temperature of the greenhouse was $13.7{\sim}20.1^{\circ}C$ and minimum ambient temperature was $-20.8{\sim}4.8^{\circ}C$, the annually accumulated heat and power consumption were 520,623 kW, 142,304 kW, respectively. Conclusion: When the set temperature of the greenhouse was $13.7{\sim}20.1^{\circ}C$ and the minimum ambient temperature was $20.8{\sim}4.8^{\circ}C$, the annually accumulated heat and power consumption were 520,623 kW, 142,304 kW, respectively. When operating only one heat pump unit, the heating COP was 2.0~3.3, and when operating 2 heat pump units, it was 3.7~4.5. If several heat pumps are installed in one GHPS, it is suggested that all heat pumps be operated except in special cases. Because the scale of the water pumps are set to the scale of when all heat pump units are operating, if even one unit is not operating, the power consumption will increase. That becomes the cause of COP decrease.

• Journal of Food Hygiene and Safety
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• v.24 no.1
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• pp.12-18
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• 2009

This experiment was conducted to investigate the effect of wa-song (Orostachys japonicus A. Berger) extracts on the oxidative stability of edible oil. Wa-song was dried from hot air (HWE) and freeze (FWE), and then they were extracted by hot water. The different levels (0.1, 0.5 and 1.0 g/100 mL) of HWE and FWE were added to soybean oil and lard. The chromaticity of edible oils was generally increased with prolonged heating time and HWE was higher than FWE. The anisidine value showed significant increase during heating for 48hrs. After heating for 48 hrs, it was lower than control, except for HWE added sample of 0.5 and 1.0 g/100 mL, FWE added sample of 1.0 g/100 mL. In lard, it was lower in sample added wa-song extract than control. The acid value was not significant by added amount of wa-song. Its value in HWE added sample was lower than FWE, after heating for 48 hrs. POV was lower HWE than FWE, also. After heating for 24 hrs, TBA values in soybean oil containing HWE and FWE added sample was lower than control. In lard, its value in HWE and FWE added sample was lower than control during heating for $12{sim}48\;hrs$. Therefore, those results suggested that HWE has higher antioxidant activity than FWE added sample, and then oxidative stability of HWE in edible oil was more potential for lard during its heating.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.73-80
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• 1998

This experiment was carried out to investigate the effect of runner development based on production period and to investigate the yield in different cropping type to nursery plant age. In runner development experiment, heating + lighting + $GA_3$ + cluster removal treatment increased the number of runners by 13.1 times higher in spring season than control(heating only) in overwintering mother-plant. Treatment of 20ppm $GA_3$ was the most effective for runner production in autumn. In nursery plant age experiment, 60 days old nursery plants produced more flower cluster than 40 days old ones. This result indicated that the yield potential was so low that overwintering runners would be adaptable for spring or summer cultivation.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.2 s.38
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• pp.127-138
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• 1991

The aim of the present stud)r has been to obtain new and additional data allolwing a better design of sports garments as well as a better choice among some materiales, through measure-ment of body surface changes in the upper trunk in movement, measurement on the effects of local heating on other parts of the body and measurement of the thermal resistance of 6 types of materials applied on a manikin. In the first experiment, the upper trunk was divided in 32 Parts, the surface of which was measured by the tape method for two upper limb positions: extension at $90^{\circ}$ and $180^{\circ}$. In the second experiment, skin temperature, local thermal sensations and whole body thermal sensation were measured every 5 minutes during 40 minutes. The four areas of the shoulder, abdomen, hande and feet were heated with the hot pack at $50^{\circ}C$. In the third experiment, the regional thermal resistance of the various materials selected, in two different cases of clothing ease, have been measured by using a thermal manikin. Resultes of experiments were: 1. Extensions cause the upper front part of the trunk surface to lengthen vertically while the back tends to stretch in width. 2. Skin temperatures of the upper limbs are influenced by the abdomen and shoulder boatings. The correlation between the whole body thermal sensation and the upper trunk thermal sensation is significantly asserted. 3. Ceramic and aluminium coated materiales offer the most effective thermal resistance; ease in clothing increases the thermal resistance at the breast and the abdomen as well as the clo value of the materials.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.3
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• pp.8-16
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• 2014

Heating and hot water supply energy consumption of medium and multi boiler systems applied to military officer housing are compared with in-situ experiment and TRNSYS dynamic simulation program. In a multiple boiler system, small capacity boilers are connected in parallel to meet the required capacity. For handling partial loads, medium capacity boiler relies on on-off control, while multi boiler adopts PI control. Since multi boiler has higher efficiency and better control strategy, the results show that energy consumption can be reduced significantly with the multi boiler system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.422-427
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• 2012

This study investigates on the relationship between total load which is caused by infiltration and insulation thickness against compensation effect. As the result of experiment, the PVC(Synthetic resins sash) window frame in airtightness is superior to the AL(Aluminum sash) window frame. In this study, as the increasing of insulation thickness in reference building does not reduce significantly cooling load, the compensation effect due to airtightness against infiltration is very small. But the compensation effect against infiltration can be closely related with heating load. Therefore, the proper thermal insulation thickness can be needed respect to cooling and heating load.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.198.2-198.2
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• 2010

In this study, the COP variation with the duration of Ground Source Heat Pump (GSHP) systems operation was analyzed by experiment. This experimental facility was installed in residential house as a back-up device of solar thermal heating system. The capacity of heat pump is 2.5 kW with a vertical bore hole of 150m depth. The COP of GSHP is varied, depending on the ground temperature which is used as a heat source. The ground heat source temperature influencing heating COP is the soil or rock temperature which adjoin with geo-source heat exchanger. This temperature is decreased rapidly according to the operation duration of heat pump. As a result, COP of GSHP is decreased to 3 in one hour of continuous operation time.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.121-126
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• 2005

Micro wires manufactured by the straightening process are used in the BT(Bio-Technology), IT(Information-Technology), NT(Nano-Technology). We have developed a novel wire straightener which uses the direct heating method(DHM) for straightening the micro wire and shearing device for burr-less cutting. In this study, we confirm the tendency of micro wire after the shearing process. It is impossible to remove the burr in the shearing process. However, the embodiment of minimum burr size after the shearing process is the best in-process method. In order to minimize the burr size, we have accomplished the various experiment condition such as the U-groove, the effect of the counter punch, the shear angle, clearance.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2131-2137
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• 1993

This study, examines the performance and the heat pump cycle systematizing characteristics for non-azeotropic refrigerant systems. In order to conduct such an examination, the cycle characteristics of heat pumps for pure R-22, R-114, and their mixtures were experimentally investigated. The results show that cooling/heating capacities for the mixtures was more suited at the evaporating temperature of $5^{\circ}C$ than that of $0^{\circ}C$, $-5^{\circ}C$, and $-10^{\circ}C$. The C.O.P of the 50 wt% mixtures was considerably higher than for pure R-22, and the compression power of the 25 wt% was as much as 60% lower than that of pure R-22. Even small fractional mixture variations can lead to significant changes in the characteristics of the heat pump cycle. This experiment verified the importance of accurate weight fractions of refrigerant mixtures.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.105-110
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• 1999

The elementary experiment was performed to develop the emulsified fuel production system using pressure injection nozzle in this study. The stabilities and characteristics of emulsified fuel which is produced through direct spray of water via pressure injection nozzle into oil are examined. To understand performance of emulsion production, stabilities of emulsified fuel which is made by adding water to the mixed fuel of Bunker-C and 10 $^{\sim}$ 50 vol% of heating oil were investigated. According to volume ratios of surfactant in heating oil the stability and SMDs were measured